Two innovative crew transfer vessels for Esbjerg-based World Marine Offshore are on course for delivery by the end of 2019, the company said
The crew transfer vessels (CTVs) are being built at Assens shipyard in Denmark. The ‘Inertia PM5’ vessels have a hybrid hullform that combines the benefits of a trimaran and a small waterplane area twin hull (SWATH).
Apart from the innovative hullform designed to reduce fuel consumption and emissions whilst ensuring they are stable, comfortable platforms for windfarm technicians to live on, they also have an upgraded version of World Marine Offshore’s active ‘Soft Bow,’ an active, impact-reducing system built into the hull of the vessel that reduces the load on a boat landing on an offshore wind turbine. The company claimed that earlier versions of the Soft Bow reduced the load imparted on a boat landing by around 50%.
Compared to World Marine Offshore’s other hybrid trimarans, the new vessels also have a number of other upgrades. These include active interceptors, active hydrofoils, two 100 kW bow thrusters for enhanced manoeuvrability and five waterjets (three in their centre hull and one in each side hull). The vessels also have a diesel-electric setup, with battery package, which can further reduce emissions.
World Marine Offshore said the vessels will be able to undertake transfers in sea states exceeding a significant wave height of Hs 2.0 m and stay offshore for more than a week. “This will guarantee our clients the best possible utilisation and offshore accessibility,” said the company. The Inertia PM5 can transport 24 passengers in business class seats or alternatively accommodate 12 passengers in six twin cabins. The design will enable passengers and crew to remain offshore for up to 10 days, the company claimed.
The trimaran hull shape confers the ability to operate at high speed with reduced fuel consumption and the SWATH ensures a high level of seaworthiness. “The trimaran gives crew and passengers optimal comfort and reduces slamming,” the company said, noting that the accommodation and wheelhouse are placed aft on the vessel to reduce heave and pitch and ensure improved comfort for both passengers and crew.
An adjustable hydrofoil is mounted at the bottom of the centre hull, which reduces heave motion and optimizes trim of the vessel. An active ride control system is installed to further reduce roll and pitch. The system also includes automatic trim and list control, compensating for cross winds or uneven loading.
In addition to working as crew transfer units, World Marine Offshore said the vessels are also suitable for a range of other tasks including undertaking surveys, using remotely operated vehicles and maintaining standby rescue and guard duties.